The disclosure relates generally to methods of firing ware to produce porous ceramic articles and particularly to methods of controlling the shape of porous ceramic articles through orientation of ware during firing.
In the manufacture of ceramic bodies, the bodies are typically extruded, dried, and fired to meet a predetermined target contour shape (e.g., having a circular or elliptical cross section). However, during such manufacture, the green bodies produced after extruding and drying have shapes with varying amounts of deviation or “mis-shape” from the predetermined target contour shape (e.g., a “slump-type” mis-shape or a “slide-type” mis-shape). This mis-shape characteristic tends to be augmented during firing such that the resulting ceramic bodies have even more overall deviation from the predetermined target contour shape than the green bodies. In the meantime, customer specifications and dimensional requirements for ceramic articles, such as those used in mobile emissions exhaust gas after treatment systems, continue to be tighter and tighter.